The table shows the airmail rates for sending letters and postcards to some countries.
Destination |
Letters |
Postcards |
|
Mass |
Postage Rate |
Per piece |
Thailand, Vietnam, Myanmar
|
1st 20 g |
$1.50 |
$0.60
|
Every additional 10 g or part thereof |
$0.20 |
How much did Mary pay for the postage when she sent a letter which weighed 94 g and 3 postcards to Vietnam by airmail?
Remaining mass that Mary had to pay for the letter as it was more than 20 g
= 94 - 20
= 74 g
Number of sets of additional 10 g of the letter that Mary had to pay for
= 74 ÷ 10
= 7 r 4
Total number of sets of additional 10 g of the letter that Mary had to pay for
= 7 + 1
= 8
Amount that Mary had to pay for the sets of additional 10 g of the letter
= 8 x 0.20
= $1.60
Total amount that Mary had to pay for the letter
= 1.50 + 1.60
= $3.10
Amount that Mary had to pay for the 3 postcards
= 3 x 0.60
= $1.80
Total amount that Mary paid
= 3.10 + 1.80
= $4.90
Answer(s): $4.90